25 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Greenstar Highflow 550 CDi
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Your boiler has failed to light the internal flame needed to heat your water, so it has shut down as a safety precaution.
Your boiler is failing to light the internal flame needed to heat your water, so it has safely shut itself down to prevent gas from building up.
Your boiler's hot water sensor is struggling to communicate with the main control board, meaning the system cannot accurately monitor the temperature of your hot water.
Your boiler has lost the signal from the sensor that monitors your hot water temperature, which means it cannot accurately heat your water.
Your boiler has detected that the internal pump, which pushes heat around your home, is not spinning correctly and the system has shut down to prevent damage.
Your boiler has lost communication with one of its internal control units, meaning it cannot properly manage your heating or hot water functions.
Your boiler has lost track of how hot the water stored inside it is, so it has safely stopped heating to prevent it from overheating.
Your boiler's internal computer has lost contact with the specific memory card that tells it how to operate your particular model.
Your boiler's fan system is failing to confirm that it is moving air correctly, which stops the boiler from firing up to prevent unsafe operation.
Your boiler has detected that the water temperature has risen too high and has temporarily shut itself down to prevent damage.
Your boiler is unable to safely drain away the water it creates while running, so it has stopped working to prevent internal flooding.
Your boiler has detected that the internal water storage tank is overfilling, which forces the system to stop working to prevent internal flooding or water damage.
Your boiler has stopped working because it has lost the connection to the sensor that monitors its internal temperature, meaning it cannot safely regulate heat.
Your boiler is currently unable to accurately measure the temperature of the water inside its internal storage tank, which means your hot water supply will not work until this sensor is fixed.
Your boiler has stopped working because it cannot detect the temperature of the water flowing through the system, likely due to a loose wire or a faulty sensor connection.
Your boiler is failing to light the internal burner, so it has safely shut itself down to prevent wasting gas.
Your boiler has detected a flame signal even though it is not supposed to be running, which is a serious safety concern as it suggests the gas valve may not be closing properly.
Your boiler is struggling to keep the flame lit once it starts, causing it to shut down for safety.
Your boiler's reset button has been held down for too long, causing the control panel to lock out as a safety precaution.
Your boiler has detected that the internal water storage tank is becoming dangerously hot, so it has safely shut itself down to prevent damage.
Your boiler has detected that the internal water storage tank has become too hot and has shut itself down as a safety precaution.
Your boiler is unable to safely drain away the water it creates during normal operation, causing it to block its own internal system and switch off.
Your boiler is failing to ignite the burner at the required power, meaning it cannot provide heating or hot water.
Your boiler is struggling to switch between providing heating and hot water, meaning you likely have no hot water available.
Your boiler is unable to safely drain away excess water produced during operation, which has caused it to stop working to prevent internal damage.
BoilerFaultCodes